Authors Kelley ME, Wan CR, Broussard B, Crisafio A, Cristofaro S, Johnson S, Reed TA, Amar P, Kaslow NJ, Walker EF, Compton MT.
Several studies suggest that adolescent marijuana use predicts earlier age at onset of schizophrenia, which is a crucial prognostic indicator. Yet, many investigations have not adequately established a clear temporal relationship between the use and onset.
We enrolled 247 first-episode psychosis patients from six psychiatric units and collected data on lifetime marijuana/alcohol/tobacco use, and ages at onset of prodrome and psychosis in 210 of these patients. Cox regression (survival analysis) was employed to quantify hazard ratios (HRs) for effects of diverse premorbid use variables on psychosis onset.
Escalation of premorbid use in the 5years prior to onset was highly predictive of an increased risk for onset (e.g., increasing from no use to daily use, HR=3.6, p<0.0005). Through the analysis of time-specific measures, we determined that daily use approximately doubled the rate of onset (HR=2.2, p<0.0005), even after controlling for simultaneous alcohol/tobacco use. Building on previous studies, we were able to determine that cumulative marijuana exposure was associated with an increased rate of onset of psychosis (p=0.007), independent of gender and family history, and this is possibly the reason for age at initiation of marijuana use also being associated with rate of onset in this cohort.
These data provide evidence of a clear temporal relationship between escalations in use in the five years pre-onset and an increased rate of onset, demonstrate that the strength of the association is similar pre- and post-onset of prodromal symptoms, and determine that early adult use may be just as important as adolescent use in these associations.
Copyright © 2016 Elsevier B.V. All rights reserved.
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Parekh JD, Wozniak SE, Khan K, Dutta SK.
The antiemetic properties of marijuana are well known, but there is increasing evidence of its paradoxical hyperemetic effects on the gastrointestinal tract and central nervous system, known as 'cannabinoid hyperemesis syndrome' (CHS). We report a case of CHS encountered in our outpatient clinic. We also completed a review of the literature using PubMed in patients over 18 years of age with CHS. Understanding the diagnostic criteria and risk factors associated with CHS may reduce the ordering of unnecessary and expensive investigations, and pursuing inappropriate medical and surgical treatments. Ultimately, abstaining from cannabis use leads to resolution of symptoms in the majority of patients.
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2016 BMJ Publishing Group Ltd.
By Heidi Heilman | March 3, 2016, 14:23 EDT
We have, for some time, known that the more marijuana there is in our communities, the more opiate and heroin use rises. Now, brain science is beginning to explain why.
Studies reveal that the cannabinoid-opioid systems of the brain are intimately connected. There is a functional interaction between the mu and Cb1 receptors of the brain and these receptors commonly exist together on brain cells. In the areas of the brain where cannabinoids bind, opioids bind as well. If you modify one system, you automatically change the other.
The mechanism is not yet well understood. With marijuana research, we are where we were in the 1920s and 30s with tobacco research linking smoking to cancer. More research is needed. But, ultimately, cannabinoids and opioids are known to strictly interact in many physiological and pathological functions, including addiction. Overall, evidence confirms a neurobiological convergence of the cannabinoid and opioid systems that is manifest at both receptor and behavioral levels
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by JENNY HOPE, Daily Mail
More than 30,000 cannabis smokers could die every year, doctors warn today.
Medical experts blame the Home Secretary for creating confusion about the risks posed by the drug - leading young people wrongly to believe it is harmless.
They claim David Blunkett's decision to reclassify cannabis as a class C drug - putting it on a level with anabolic steroids and prescription painkillers - sent out the wrong message and played down the devastating health effects of its regular use.
Professor John Henry, a leading authority on the drug, said the change - due to take place this summer - had undermined doctors' efforts to highlight the risks.
He said: "Cannabis is as dangerous as cigarette smoking - in fact, it may be even worse - and downgrading its legal status has simply confused people.
"We have a clear public message about cigarette smoking. Every year, the number of smokers gets smaller and the message on packets about the dangers gets bigger.
"At present, there is no battle against cannabis and no clear public health message."
In today's issue of the British Medical Journal, Prof Henry and other doctors from Imperial College, and St Mary's Hospital, both in London, say cannabis could be a major contributor to UK deaths.
Researchers calculate that if 120,000 deaths are caused among 13million smokers, the corresponding figure among 3.2million cannabis smokers would be 30,000.
The drug can cause cancer, lung disease and abnormalities associated with serious mental illness.
Users are up to six times more likely to develop schizophrenia.
The British Lung Foundation says smoking three joints a day can cause the same damage to the airways as a pack of 20 cigarettes.
Prof Henry added: "Even if the number of deaths turned out to be only a fraction of the 30,000 we believe possible, cannabis smoking would still be described as a major health hazard.
"If we add in the likely mental health burden to that of medical illnesses and premature death, the potential effects of cannabis cannot be ignored."
Dr William Oldfield, from St Mary's Hospital and one of the authors of the article, said: "Cannabis and nicotine cigarettes have a different mode of inhalation. The puff taken by cannabis smokers is two-thirds larger, they inhale a third more and hold down the smoke four times longer.
"All these factors could contribute to illnesses of the heart and respiratory system, particularly as the chemicals in cannabis smoke are retained in the body to a much higher degree."
He said the cannabis used today - especially that bought in the Netherlands - was up to 40 times stronger than that used by Flower Power hippies in the 1960s.
The level of active ingredient in cannabis, tetrahydrocannabinol (THC) has increased from around 0.5 per cent 20 years ago to almost five per cent today. THC affects the heart and blood vessels and many sudden deaths have been attributed to cannabis smoking.
In Britain, about eight million people admit to smoking cannabis, with at least one-third of youngsters claiming to have used it at some time. They include Prince Harry, who admitted smoking the drug while a pupil at Eton.
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Cuts against many other studies that have showed pot doesn't have fatal health implications
A recent German study claims to have documented the first known deaths resulting from marijuana use.
While researchers studied 15 people whose deaths were allegedly linked to marijuana use, 13 of those deaths were confirmed to be caused by other factors. Researchers said, however, that the drug was to blame in two isolated cases of two seemingly healthy people, one 23 years old and another 28. Autopsies found that younger had a serious undetected heart problem, suggesting that people with cardiological issues should be aware of marijuana risks, and the older had a history of alcohol and drug use.
“To our knowledge, these are the first cases of suspected fatal cannabis intoxications where full post-mortem investigations… were carried out,” researchers said in the study, published in Forensic Science International this month. “After exclusion of other causes of death we assume that the young men experienced fatal cardiovascular complications evoked by smoking cannabis.”
The new study cuts against many others showing pot use does not have serious medical repercussions. The German Association for Drugs and Addiction criticized the study on Wednesday, The Local reports.
“Cannabis does not paralyze the breathing or the heart,” said Jost Leune, who heads the group. He said the dangers of marijuana are “exaggerated” and that “deaths due to cannabis use are usually accidents that are not caused by the substance, but to the circumstances of use.”
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